10 Mr. W. L. Distant on Oriental Capsidae. 



Madagascar is quite a new area for the genus Naiadites, 

 and it has not yet been recorded from the Karoo formation 

 of South Africa, which contains other forms of fresh- 

 water bivalves, such as Palaomutela and Palceanodonta. 

 Some years since Professor Amalitzky described several 

 forms of this genus from the Russian Permian, but on a 

 closer study he found that they were Anodwita-\ike shells 

 and differed materially from the original type of Naiadites 

 of 1860; he therefore founded the new genus Palceanodonta 

 for the reception of those species (Quart. Journ. Geol. 

 Soc. 1895, vol. li. pp. 346, 347). It is now generally 

 recognized that Salter's Anthracoptera of a later date is the 

 equivalent of Dawson's Naiadites. 



EXPLANATION OF PLATE I. Figs. 6-11. 



Upper Palaeozoic (Permo-Carboniferous) Mollusca from Audogozo, on 

 the Mahavavy River, North-western Madagascar; presented to 

 the British Museum by the collector, Mr. Ueorge G. Dixon. 



Figs. Q, 7. Planorbis dixoni, sp. n. x4. Fig. 6 = basal disc view ; fig. 7 

 = counterpart of same, with obscure evidence of inner whorls. 



Fig. 8. Naiadites madagascariemie, sp. n. Internal face of nodule 

 showing the gregarious nature of the valves, slightly enlarged. 



Fig. 9. External aspect of a right valve. I Drawn from wax 



Fig. 10. ,, „ ,, left valve, j impression. X 4. 



Fig. 11. Interior of a left valve showing pallial line. X 4. 



III. — Descriptions of Oriental Capsidae. 

 By W. L. Distant. 



[Concluded from vol. iv. p. 523.] 



Azizus, gen. nov. 



Head deflected in front of eyes, longer than broad, eyes 

 large and globose, prominently projecting beyond the ante- 

 rior margins of the pronotum ; antennas somewhat long and 

 robust, first joint stoutest, a little longer than head, slightly 

 curved, second joint nearly three times as long as first, third 

 about two-thirds the length of second and nearly twice as 

 long as fourth ; rostrum passing the posterior coxae ; pronotum 

 nearly twice as broad at base as long and nearly three times 

 as broad as anterior m .rgin, the basal margin concave, trans- 

 versely constricted near anterior margin, the anterior area 

 with a small tubercle on each lateral margin, the lateral 



